When I was a Sheriff's deputy in Nevada we all carried 357s as duty guns. Many of us carried 38 cal 2" revolvers as back-ups or off duty. But my department mandated the 357 as a belt gun, and I know of no other Nevada County that didn't. Later the new county Sheriff opened it up to the officers choice as long as long as the officer could qualify. After that point in time we started seeing a mix of 357s, 45s and a few 9mms.
I know there were some town PDs that were mandating 38s as duty carry guns, but very few of them. Las Vagas PD mandated 38s for a while and then went to 9MMs.
In those days Nevada Highway patrol also mandated the 357, and so did California highway patrol as I recall. Idaho and Utah also.
One thing I have kept track of since those years is the total number of shots fired per shooting and it is a sad fact that today the average cop has a LOT more rounds at his disposal and they fire a LOT more rounds per engagement, but they hit a lot less. Reno for example, back in the early 70s was averaging 3 rounds fired per kill on bad guys and very very few were wounded.
The last set of stats I was given from Reno from the years starting in 2000 and going to about 2009 is showing about 16 shots fired per cop and in some cases no hits, in most cases there are hits and most of them are not central. In those years what I was shown and told is that over 1/2 of the bad guys shot were not killed because many were not hit well.
I personally do not think this has anything at all to do with the guns.
Nevada in the 50s and 60s was the wide open west and the "gun culture" was
the regular culture.
So men in their 20s in the 1970s were a product of the 60s and 50s when they were kids (like me) and grew up shooting. Even a lot of city boys could ride a bike to the country to shoot in less then 1 hour.
Now you just done see 12 year old boys shooting their revolvers on the weekends without "adult supervision" and even then it is rare. In most states it's not even legal anymore.
So cops are taught to shoot when they go to their academy.
In the 70s most cops went to their training with many thousands of rounds of experience already behind them. In the western states that is. (Probably not so much in California, but most other western states were that way)
In the east and midwast in the 70s the shots fired to hits made was about as it is in Nevada today. And I believe it is for the exact same reason. Guns were "controlled" and that means their use was curtailed from young boys and girls. Also the fact that in the east most people live in cities and where population is denser so practical opportunities are just not available to shoot a lot.
So like a broken record I always come back to my saying: It's not the gun that matters as much as he man shooting it.
Ok Rant over.......